Modern technology could undergo a revolution with more efficient computers, communications and sensors thanks to quantum research. However, challenges still exist in the realization of these technological goals, such as how to properly control information in quantum systems.
Researchers led by John Nichol, associate professor of physics at the University of Rochester, describe a new technique for manipulating information in a quantum system by altering the electron spin in silicon quantum dots, tiny, nanoscale semiconductors with surprising abilities.
According to Nichol, “the study's findings offer a potential new mechanism for coherent control of electron spin-based qubits in semiconductor quantum dots, which could open the door to the creation of a viable silicon-based quantum computer.”
Billions of transistors, or bits, make up a typical computer. Quantum computers, on the other hand, are built using quantum bits or qubits. Qubits are arranged according to the principles of quantum mechanics and can be both "0" and "1" at the same time, unlike conventional transistors, which can only be "0" (off) or "1" (on).
Silicon quantum dots, long seen as qubits, would allow the manipulation of quantum information transfer through the control of electron spin. Like a tiny bar magnet, every electron in a quantum dot is intrinsically magnetic.
Since each electron is a negatively charged particle that behaves as if it is spinning rapidly, scientists refer to this magnetic moment as "electron spin" because it is this efficient motion that causes magnetism.
Because a large gate has long coherence times, electron spin is a suitable choice for transport, storage, and processing of information in quantum computing. It can also be produced using sophisticated semiconductor fabrication methods. The amount of time a qubit has before quantum information is lost as a result of interaction with a noisy environment is known as coherence time; a long consistency indicates a longer computation time. High gate accuracy indicates that the attempted quantum action is performed exactly as desired.
New Way of Controlling Qubits Found
Controlling electron spin is a major challenge when using silicon quantum dots as qubits.
Electron spin resonance (ESR), which requires qubits to be exposed to fluctuating radiofrequency magnetic fields, is the traditional technique used to regulate electron spin. However, this approach has a number of drawbacks, such as the need to generate and properly manage oscillating magnetic fields in cryogenic environments where most electron spin qubits are used. Researchers typically conduct a current through a wire to produce oscillating magnetic fields, but this can disturb the cryogenic environment as it generates heat.
Nichol and colleagues describe a novel approach to regulating electron spin in silicon quantum dots that does not rely on fluctuating electromagnetic fields.
The technique is based on a phenomenon known as "spin-valley coupling", which occurs when electrons in silicon quantum dots switch between various spin and valley states. The valley state of an electron refers to a discrete attribute dependent on the spatial profile of the electron, while the spin state of an electron refers to its magnetic properties.
The spin-valley coupling effect is used by researchers to regulate spin and valley states, which in turn controls electron spin.
Unlike ESR, which requires oscillating magnetic fields, this consistent control technique with spin-valley coupling provides ubiquitous control over qubits. This opens up a new avenue for information manipulation in quantum computers using silicon quantum dots.
Source: thequantuminsider
Günceleme: 30/01/2023 20:09
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